.300 Black Out Pistol vs Carbine Gas length tube

[USMC Arty]

So, this question my have already been asked and if so, then I apologize. Or this may just be a stupid question and if so then again; I apologize. That being said: I keep reading that one of the ways to ensure that an AR chambered in .300 Blackout on a 16" barrel cycles properly is to have a pistol length gas tube. I get this. It makes sense that there will be more gas pressure closer to the chamber. But, does this not affect the velocity of the round since you are pulling off the gasses that propel the round with around 6" still left for the round to go down the barrel. I feel like if you have a 16" barrel with a pistol length gas tube you have pulled away much of the propulsion but the bullet is still being affected by the friction in the barrel.

[MegademiC]

Gas port size limits bleedoff.
I know gas vs bolt velocity tends to be 100-150 fps different iirc.
I dont think you will see a statistically significant difference between gas system location.

[Clint]

Gas length won't have a meaningful effect on velocity.

A pistol length gas is recommended for cycling both subs and supers.

A carbine is probably the better choice for supers only.

[lysander]

I know gas vs bolt velocity tends to be 100-150 fps different iirc.

I am certain it is not that high, and I seriously doubt the difference is reliably measurable....

[MegademiC]

I am certain it is not that high, and I seriously doubt the difference is reliably measurable....

I was going off incorrect memory.
A recent search looks to be 20-30fps.
It probably varies gun to gun as well.

Big picture: it’s insignificant

[USMC Arty]

I was going off incorrect memory.
A recent search looks to be 20-30fps.
It probably varies gun to gun as well.

Big picture: it’s insignificant

that sounds a lot better. 100 -150 ftps was a little concerning since that is 10- 15% of a subsonic load.